Rihanna's 'Stay' is one of the standout cuts from her 'Unapologetic' album, as well as one of the biggest hits of the year -- and, with its ascent to the top spot on Billboard's Pop Songs chart this week, it's also a new career milestone for her.

Billboard reports that Rihanna's latest No. 1 hit is especially significant because it puts her ahead of some pretty elite company -- in fact, she's become the first artist in the 20-year history of the Nielsen-powered Pop Songs chart to accrue 10 of them. As their article notes, it's an especially impressive feat given that she's only been releasing hit singles since 2006's 'SOS.'

As fast as Rihanna's exerted her chart dominance, she's going to have to keep racking up those hits if she wants to stay on top of the record books. 'Stay' breaks a tie with Katy Perry, who's been on the scene for an even shorter period of time -- she's been charting only since 2008 -- and whose nine No. 1s have been culled from two studio albums as opposed to Rihanna's seven.

Given that Perry is just about due to release her follow-up to 2010's 'Teenage Dream,' we could soon be witnessing a back-and-forth battle for all-time Billboard supremacy.

Watch the Rihanna 'Stay' Video